Posted
by
Soulskill
on Tuesday January 10, 2012 @03:45PM
from the plantlife-now-obsolete dept.

sciencehabit sends this excerpt from ScienceNOW: "Researchers in California have produced a cheap plastic capable of removing large amounts of carbon dioxide (CO2) from the air. Down the road, the new material could enable the development of large-scale batteries and even form the basis of 'artificial trees' that lower atmospheric concentrations of CO2 in an effort to stave off catastrophic climate change."

The polymer could be useful for building massive farms of artificial trees that would aim to reduce atmospheric concentrations of CO2 and prevent the worst ravages of climate change. But that's only if countries around the globe are willing to spend untold billions of dollars to rein in atmospheric CO2.

It also says:

So you have to expend a fairly large amount of energy heating the media to 85C/185F to get it to give up the CO2, (then more energy to store the CO2).How long it takes to saturate the polymer is not mentioned, but unless its months between regeneration, the CO2 generated while collecting the polymer media, transporting it to a facility, HEATING it, capturing the recovered CO2, could exceed the amount it could capture. And then you are still left with the CO2 you captured. What to do with that?

So the original purpose of this polymer, to keep C02 out of batteries seems to be a far better use for the polymer than environmental CO2 sequestration.

To where? Still what hasn't been accounted for is the amount of energy required to produce the polymer. It's probably a petroleum based polymer which requires oil extraction, shipping, processing in a refinery and/or chemical plant, and manufacture. I want to see mass and energy balances. The softer approach of planting trees is probably still the best approach when compared to energy intense Engineering approaches. Trees also have the advantage of binding up water vapour, which is a green house gas much more powerful than CO2.

It means the CO2 can be extracted from the absorber (PEI) by heating the material (after saturate it with CO2) up to 85c. This is not that much energy to extract the CO2 out as compared to other CO2 absorbers.

But I still agree that trees would be the best way to deal with CO2. The article said that his original idea of trapping CO2 is to combine it with Hydrogen to produce methanol fuel (as below quoted).

"he (Olah) suggests that society could harvest atmospheric CO2 and combine it with hydrogen stripped fro

The point is to eventually catalyze everything to long chain hydrocarbons, e.g. Octane. Liquid at room temperature and pressure, high energy density. Way higher than any battery. Gasoline is gasoline because it is a damn efficient way to store energy and release it later under controlled circumstances and turn it into work.

The reason to harvest the CO2 is that while it's in the atmosphere at current levels (let alone another 100 years worth of emissions) it's going to cause us problems. Pull it out of the atmosphere and do something useful with it is the only solution that will turn things around.

That said, reducing current emissions is the first step. Harvesting existing CO2 is probably step 10 or 11 down that path.

If only they could figure out a way to make them self replicating, then set them up to turn the CO2 into something useful, I don't know, how about (and I know it's crazy) sugar? And the whole thing could be solar powered, yeah that's the ticket...

To where? Still what hasn't been accounted for is the amount of energy required to produce the polymer. It's probably a petroleum based polymer which requires oil extraction, shipping, processing in a refinery and/or chemical plant, and manufacture. I want to see mass and energy balances. The softer approach of planting trees is probably still the best approach when compared to energy intense Engineering approaches. Trees also have the advantage of binding up water vapour, which is a green house gas much more powerful than CO2.

What do you do once you have a forest full of trees? You can't just keep planting them indefinitely or you'd run out of room for forests. Cut them down and bury them? Is there some other way to sequester the carbon?

Cutting them down and using them for anything other than burning them (or letting them decay) would sequester the carbon they had captured for relatively long periods of time. That does actually include burying them as long as it is in a way that would deter natural decay (many of the bacteria involved release CO2).

* Build houses and furniture out of it* Use pyrolysis (partial burning without enough oxygen) to create char products (essentially make charcoal). Add it to soil. It improves the nutrient holding capacity of soil and takes a long time to decay itself when buried (~200 years). The reason it holds nutrients is charred wood has lots of tiny holes in it from the plant cells. Nutrients don't get washed away as easily. Holding more nutrients allows the next generation of trees to grow faster, or feed more people, depending what you use the land for. Pyrolysis also generates a bit of energy as a side effect.* Store the wood in a dry or cold location where it won't rot. There are plenty of deserts and ice caps for that. If you put it on ice, wood is a good insulator, and can reduce melting of glaciers by keeping the sun off them in the summers. That won't make a difference in the middle of Antarctica, but it can help around the margins of ice caps where melting is happening.

I used to be a tree farmer, you insensitive clod! (Really, no joke, I was). Planting trees makes plenty of money, even without carbon trading offsets. If you can get credits for CO2 removal, it is even more profitable.

I never cut my trees down, and still made money with it, because the "standing timber" increased in size while I owned it, and therefore was worth more as an asset. You have to buy a forest which is not mature for that to work. Mine were ~20 years old when I bought them, old enough to reach peak growth. Seedlings don't build much lumber volume the first few years. After some time, the maturing trees slow down their growth and some start dying off, so at that point you can start to harvest at a steady rate, and planting replacements for the ones you harvest to maintain growth. When that happens depends on which kind of tree it is.

Trees don't really control the amount of water vapor in the atmosphere; they don't sequester a large amount of water for a long time. To first order, the amount of water vapor in the atmosphere is controlled by temperature.

Planting trees doesn't remove the CO2, it jsut hold it temperarly.Half of the CO2 gathered during the day is released at night, the other half id given up when it rots.

They said the same thing about storing Carbon in Coal. Its just temporary.

Forests do not all give up half the CO2 gathered at night. In fact Trees sequester about 70+ pounds per tree per year. They make it into wood.The tree eventually dies. 50 to 200 years later.The wood rots 5 to 30 years later.But the forest keeps growing.New trees feed off of the old rotting trees.The carbon is sequestered for as long as the Forest stands.

You can't look at one tree and shrug it off as a zero sum game.The living trees, the dead trees, the leaf litter on the ground, the humus of the soil hold ton upon tons of CO2.

Weigh the forest, living dead, and 10 feet of humus. Put it all on the scale. The whole damn thing.Divide by 3. That's roughly the weight of the carbon sequestered by the forest. Forever, as long as you let it grow.

Sorry mate, entropy. Having gained energy by combining Carbon with air, you must put in energy to get your carbon back. All you end up with is a huge/complicated/inefficient battery. AS there are already large amounts of carbon lying around natrually (coal) , it probably isn't worth it.

Extracting the carbon out of CO2 is going to require more energy than you'll ever be able to get from burning the products. You don't want to use fossil fuels to power that or else you're going to end up with a net increase in CO2 emissions.

Yesterday, wasn't the general consensus from the scientific community that we were 1500 years off from the next ice age, and that the current concentrations of CO2 in the atmosphere would result in pushing that off for at least another 1000 years?

We as a species should just decide on whether we want to live in the tropics or the arctic. This constant back and forth is getting tiring.

You probably wouldn't like your car quite so much if you had to pay full price for the roads, and if cities didn't force businesses to overbuild parking lots, and if the negative externalities of gasoline use were added to the price of gasoline.

In short, you're being bribed and coerced into driving. So forgive me for not believing you.

He (we) do pay full price. At the dealership, the gas pump, and on our tax bill. These things don't build themselves you know. As a society we decided to build them and we pay the full price. Try Macro Economics 101 at your local community college.

No. Yesterday there was an article about one small group of scientists who claim that the next ice age should begin in 1500 years based on the frequency of ice ages in past history. One group's predictions hardly qualifies as "general consensus from the scientific community."

Yesterday, wasn't the general consensus from the scientific community that we were 1500 years off from the next ice age, and that the current concentrations of CO2 in the atmosphere would result in pushing that off for at least another 1000 years?

Well then there is that whole ocean acidification thing. Rising temperatures aren't the only effect of climate change. There is no free lunch here.

I often wonder where people who deny pollution is having any effect on the earth think they are going to live if they are wrong.

Probably figure they'll live right next door to the "terr'ists behind every tree stump so we must molest all Americans" FUD farmers. They should get along famously, similar outlook of controlling the populace thru terror, etc.

So you have to expend a fairly large amount of energy heating the media to 85C/185F to get it to give up the CO2, (then more energy to store the CO2).How long it takes to saturate the polymer is not mentioned, but unless its months between regeneration, the CO2 generated while collecting the polymer media, transporting it to a facility, HEATING it, capturing the recovered CO2, could exceed the amount it could capture. And then you are still left with the CO2 you captured. What to do with that?

So the original purpose of this polymer, to keep C02 out of batteries seems to be a far better use for the polymer than environmental CO2 sequestration.

With a requirement of only 85 C, they could easily be heated using low-grade waste heat from a process plant, or using a solar concentrator or similar. No additional energy expenditure required. It would also probably be done locally, so there would be little to no transport cost. There will still be some cost to recover and contain it, but it should still be an overall reduction of CO2. There are multiple uses for the CO2, that should not be a problem.

Missing it entirely:
One gram adsorbs 1.72 billionths of a mole of CO2. So a billion grams will absorb 1.72 moles of CO2. IIRC a billion grams is 1000kg, or one tonne. To absorb 75.68 grams (1.72 moles) of CO2. Yeah, that will work.

There is a typo in the article summary. The polymer material will reportedly absorb 1.71 mmole (millimoles = 1 x 10^-3^ moles) of CO_2_ per gram of the polymer. A lot better than nmoles (nanomoles = 1 x 10^-9^ moles), but your point still stands, they'll have to do a lot better CO_2_ per gram of polymer to have any atmospheric impact. Also, one mole of CO_2_ has a mass of 44.01 grams, not 75.68.

Wait, wait... so if we take the wood and turn it into charcoal by outgassing, compress the charcoal, and then store it in underground caverns, maybe, oh, I don't know, um, old coal mines, the cycle will be complete!

Kidding aside, it sounds like a good idea and, with some effort, could be part of a long-term shift in energy source from coal to processed wood, which is probably a good thing, especially if the outgassing products are trapped and used for raw materials.

So you'd need 9.1kg / 75ng = 120 billion grams of the material to absorb the CO2 output from a gallon of gas.

I don't know the density of this new material or its substrate, but if it's similar to common plastic tarps... A 20x100 foot roll of 10mil plastic film weighs 95 lbs [globalplas...eeting.com] (which probably includes the cardboard spindle).

Lol, you can be the first to give up your house to the new reforestation act then. I think rather than trying to reduce the carbon, how about we stop producing it? Somewhere between nuclear power & electric cars fueled off that power.

I have planted no less than 16 trees on my property in the 7 years I've lived there. I would plant more if only my wife and city regulations would let me (I'm banned from planting mulberry due to pollen concerns, for example.) No need to give up my house in order to have some reforestation!

I'm in favor of reducing carbon output by producing electricity with nuclear or other non-carbon-releasing options.

No need to remove houses. We have plenty of land to grow trees. What we don't have is enough fresh water. Enter desalinization plants. Add a bunch of them near the U.S. coast, and pump metric craptons of fresh water into the grasslands and deserts in the middle of the U.S. Take advantage of the now-arable land to grow forests.

I don't think of myself as an environmentalist or anything like that. I'm all for better energy efficiency and cleaner forms of energy, but something like this strikes me as rather dumb. You have to spend energy making these things, and then energy running them, not to mention time and money all to remove a bit of CO2 out of the air. Wouldn't it make more sense to plant more trees instead, and spend the rest of your time and money on cleaner and more efficient methods of powering well everything?

I don't deny that climate change is happening, it's always been happening and I believe that we have some impact on the way it changes, so being as responsible as we can with what we do with 'waste' like CO2 or other byproducts is always important, but things like this in the modern "green" movement just make me shake my head in disbelief.

Wouldn't it make more sense to plant more trees instead, and spend the rest of your time and money on cleaner and more efficient methods of powering well everything?

It would make more sense not to put the CO2 into the air in the first place. But if you're going to pull it back out again, it remains to be seen whether artificial trees or real trees have the best cost/benefit ratio. It takes really, really huge forests to make a dent in atmospheric CO2 and reforesting the whole planet won't get CO2 back down to pre-industrial levels any time soon. Maybe a large industrial operation could do better, if the tech improves and economies of scale set in.

...could we just plant regular ones? If even that is too much of a problem for most countries, we should maybe forget about expensive artificial stuff.
Yes, expensive, regardless of what TFA says, because there's nothing cheaper than a real tree.

I welcome this kind of innovations very much.But to be honest I think at the moment our biggest problem is our global energy consumption.I can do without my computer for a week if we're low on fuel, but food...

Everyone has this idea that the "obvious" solution to our carbon/energy/global warming problems is to reduce consumption. I'm especially amused by authors who try to "guilt" the US into reducing consumption in order to let other cultures have a "fair share" at dwindling resources.

This is poppycock, and it's the wrong solution.

The reason the US has such a high consumption is that people *like* this level of consumption and there should be nothing wrong with that.

The thought of giant CO2 scrubbing plastic trees seems like hyperbole to me. Seems we could plant real trees that work about as well for that. But an obvious application jumped out at me. Undersea vehicles, labs, manned spacecraft, and any other artificially maintained environment that humans have to work in need to remove CO2 because it can be poisonous in sufficiently high concentrations even if there is enough to breathe.

So would this material make good scrubbers for sealed environments people have to work in? If there is a way to vent the waste gases, being able to drive the CO2 off with a bit of heat and using again seems a great feature too.

Currently, we're extremely efficient at cranking gigatons of carbon into the atmosphere. Assuming for a moment that fake tree manufacturing was extremely energy efficient and carbon neutral, that's a lot of work just to keep up with conveyor-belting coal into power plants and pouring fuel into our vehicles.

However, tree manufacture won't be all that efficient, meaning we'd need several times more fake trees to compensate. Nice out-of-the-box try there, boys, but this dog won't hunt.

But the atmosphere is basically saturated with water, and its greenhouse contribution (something on the order of 20C IIRC) is part of the baseline climate with or without humans. In other words water vapor's contribution to climate change is zero, since the amount hasn't (can't have) risen or decreased meaningfully since the dawn of civilization.